The Responsible Mind in South African Criminal Law (PhD Thesis)

South African criminal law has accepted that it is only fair to punish those who are responsible for doing wrong. Responsibility – that the accused must be blameworthy – finds expression in several specific requirements of South African criminal law: voluntariness, fault, and in particular, capacity (into which the insanity defence falls). This thesis critically analyses these requirements. It includes an empirical component in which forensic psychologists and psychiatrists (on whom our courts are relying for guidance in cases where responsibility is in question) were consulted on what they understand these various requirements to mean. The thesis also identifies and critically analyses the underlying model of responsibility adopted in our law and considers the alternatives. The conclusion from the empirical component and critical analysis is that the specific requirements are unclear and even incoherent and that this is a function of the underlying model of responsibility which identifies random capacious and arbitrary conduct as responsible conduct. Alternative models of responsibility are discussed from which the compatibilist model of reason sensitivity is selected as a better foundation for criminal responsibility. The implications of adopting this model for the various specific requirements of South African criminal law are discussed and appropriate modifications are proposed. Again the opinions of the forensic experts were sought and the proposals were overwhelmingly endorsed. Ultimately a new model of criminal responsibility and a revised set of specific requirements are proposed, together with a proposed new statutory test for responsibility.

This is a little mysterious to me.
On the one hand, our Courts insist that they are the final adjudicator of what amounts to a “mental illness” but it is not defined in statute, nor by our courts.
They recognise that expert evidence is required because our courts are not experts in mental health. Yet, and this is my, no doubt, controversial opinion, I don’t know how a mental health expert can know what questions to answer so as to assist the court to recognise a mental illness, or what the court will/can consider, if no one knows what a “mental illness” is.